Cytek Biosciences (CTKB) CTO granted stock options and 227,535 RSUs

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(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Cytek Biosciences, Inc. director and Chief Technology Officer Yan Ming reported several equity compensation transactions. On March 10, 2026, Ming received an employee stock option for 120,688 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years. He also received 227,535 Restricted Stock Units (RSUs), which vest over four years in specified tranches each May 18, August 18, November 18, and March 10 according to the award schedules.

Ming exercised previously granted RSUs covering a total of 25,400 shares of common stock. Of the resulting shares, 7,731 shares were withheld and surrendered to Cytek Biosciences at $4.23 per share to satisfy tax withholding obligations, and the remaining shares increased his direct common stock holdings. After these transactions, Ming directly owned 6,091,933 shares of common stock.

Insider Trade Summary

25,400 shares exercised/converted

Mixed 11 txns

Insider Yan Ming

Role CHIEF TECHNOLOGY OFFICER

Type	Security	Shares	Price	Value
Grant/Award	Employee Stock Option (right to buy)	120,688	$0.00	--
Grant/Award	Restricted Stock Units	227,535	$0.00	--
Exercise	Restricted Stock Units	9,817	$0.00	--
Exercise	Restricted Stock Units	7,366	$0.00	--
Exercise	Restricted Stock Units	8,217	$0.00	--
Exercise	Common Stock	9,817	$0.00	--
Tax Withholding	Common Stock	3,047	$4.23	$13K
Exercise	Common Stock	7,366	$0.00	--
Tax Withholding	Common Stock	2,287	$4.23	$10K
Exercise	Common Stock	8,217	$0.00	--
Tax Withholding	Common Stock	2,397	$4.23	$10K

Holdings After Transaction: Employee Stock Option (right to buy) — 120,688 shares (Direct); Restricted Stock Units — 227,535 shares (Direct); Common Stock — 6,084,081 shares (Direct)

Footnotes (1)

Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award. The shares subject to the stock option shall vest over 4 years with 1/48 of the total shares underlying the stock option vesting on April 10, 2026 and each month thereafter until fully vested. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting November 18, 2026 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2027 and each March 10 thereafter, until fully vested. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2023 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2023 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2023 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2024 and each March 10 thereafter, until fully vested. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2024 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2024 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2025 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2026 and each March 10 thereafter, until fully vested.

Form 4 Insider Transactions: What Each Field Means →

03/12/2026 - 04:36 PM

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Yan Ming

(Last)

(First)

(Middle)

C/O CYTEK BIOSCIENCES, INC.

47215 LAKEVIEW BOULEVARD

(Street)

FREMONT

94538

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
Cytek Biosciences, Inc. [ CTKB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	CHIEF TECHNOLOGY OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	03/10/2026		M		9,817	A	⁽¹⁾	6,084,081	D
Common Stock	03/10/2026		F		3,047⁽²⁾	D	$4.23	6,081,034	D
Common Stock	03/10/2026		M		7,366	A	⁽¹⁾	6,088,400	D
Common Stock	03/10/2026		F		2,287⁽²⁾	D	$4.23	6,086,113	D
Common Stock	03/10/2026		M		8,217	A	⁽¹⁾	6,094,330	D
Common Stock	03/10/2026		F		2,397⁽²⁾	D	$4.23	6,091,933	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Employee Stock Option (right to buy)	$4.23	03/10/2026		A		120,688		⁽³⁾	03/09/2036	Common Stock	120,688	$0	120,688	D
Restricted Stock Units	⁽¹⁾	03/10/2026		A		227,535		⁽⁴⁾	⁽⁴⁾	Common Stock	227,535	$0	227,535	D
Restricted Stock Units	⁽¹⁾	03/10/2026		M			9,817	⁽⁵⁾	⁽⁵⁾	Common Stock	9,817	$0	29,460	D
Restricted Stock Units	⁽¹⁾	03/10/2026		M			7,366	⁽⁶⁾	⁽⁶⁾	Common Stock	7,366	$0	44,203	D
Restricted Stock Units	⁽¹⁾	03/10/2026		M			8,217	⁽⁷⁾	⁽⁷⁾	Common Stock	8,217	$0	73,958	D

Explanation of Responses:

1. Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.

2. Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award.

3. The shares subject to the stock option shall vest over 4 years with 1/48 of the total shares underlying the stock option vesting on April 10, 2026 and each month thereafter until fully vested.

4. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting November 18, 2026 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2027 and each March 10 thereafter, until fully vested.

5. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2023 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2023 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2023 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2024 and each March 10 thereafter, until fully vested.

6. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2024 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2024 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter.

7. The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2025 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2026 and each March 10 thereafter, until fully vested.

	/s/ Valerie Barnett, Attorney-in-Fact	03/12/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

Source: View Original Filing on SEC EDGAR

FAQ

What equity awards did Cytek Biosciences (CTKB) CTO Yan Ming receive?

Yan Ming received an option to purchase 120,688 shares at an exercise price of $4.23 and 227,535 Restricted Stock Units. Both awards vest over four years under detailed schedules tied to specific May, August, November, and March vesting dates.

How many Cytek Biosciences (CTKB) shares does Yan Ming hold after this Form 4?

After these transactions, Yan Ming directly holds 6,091,933 shares of Cytek Biosciences common stock. This figure reflects RSU conversions into common stock and share withholding for taxes, as reported in the non-derivative transaction table for March 10, 2026.

Were Yan Ming’s Cytek Biosciences (CTKB) transactions open-market buys or sales?

No, the filing shows no open-market purchases or sales. The transactions are equity compensation events: option and RSU grants, RSU conversions into common stock, and F-code dispositions where shares were withheld and surrendered to cover tax obligations arising from vesting.

How do Yan Ming’s new Cytek Biosciences (CTKB) RSUs vest?

Each Restricted Stock Unit represents one share of common stock and vests over four years. Portions vest on recurring May 18, August 18, November 18, and March 10 dates, with differing 2/48, 3/48, and 4/48 fractions until the award is fully vested.

What does the F-code tax withholding in the Cytek Biosciences (CTKB) Form 4 mean?

F-code entries show 7,731 shares of common stock were withheld and surrendered at $4.23 per share. These are not open-market sales; they represent shares delivered back to Cytek Biosciences to satisfy tax withholding obligations when RSU awards vested on March 10, 2026.

When do Yan Ming’s Cytek Biosciences (CTKB) stock options expire?

The employee stock option granted to Yan Ming on March 10, 2026 expires on March 9, 2036. The option vests monthly over four years, with 1/48 of the total option shares vesting on April 10, 2026 and each month thereafter until fully vested.